Ball and Socket joint assemblies and other types of pivot joints include an annular socket having a radially outer surface. A ball stud with a ball and shank are received in the socket such that the ball is enclosed in the socket while the shank extends away from the socket. The ball stud pivots and oscillates about the center of the ball. A dust boot is typically used with a ball and socket joint assembly to provide a sealing barrier against the entry to the assembly interior of dirt, water and related foreign material while simultaneously limiting the undesirable leakage of any lubricant used to promote assembly operation. Despite its sealing functions, however, the dust boot must provide for complete freedom of movement of the ball stud.
Typically, a dust boot is formed from an elastomeric material and includes two end portions. A first end portion cooperates with the radially outer surface of the socket while a second end portion cooperates with the ball stud shank. To promote sealing engagement it has been known to embed an annular retaining ring in at least one of the end portions to provide additional support. However, traditional retaining rings require very tight tolerances between the dust boot and the mating surface. As a result, the mating surface is typically machined. Yet, it is preferable to use forged sockets and shanks with greater tolerance ranges because of the reduced cost of production. One solution that has been proposed for retaining rings embedded in the end portion of a dust boot engaging the radially outer surface of a socket include the use of a circular array of fingers or tabs extending radially inwardly from a main body. Relatively short fingers position the end portion of the dust boot while relatively long fingers retain the dust boot in place. While the use of retaining rings with simple radially extending fingers may be adequate in the end portion of a dust boot associated with the annular socket, such a retaining ring is inadequate for use in the end portion engaging the ball stud shank. Unlike a fixed socket housing, a ball stud shank is subjected to extensive oscillation and pivoting during normal joint operation. As a result, it is particularly difficult to maintain a constant radial load between the dust boot end portion and the shank over the entire range of shank movement.